Slovak University of Technology
Faculty of Material Science and Technology in Trnava
Machine Tools And
Devices For Special
Technologies
Ultrasound machining
Machining by ultrasound
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ultrasound – acoustic oscillation with frequency
higher than 20 kHz.
sonar – first using of ultrasonic in the beginning
of 20th century
Ultrasonic machining – process that used
ultrasonic (mechanical acoustic oscillation) for
material removing with destroy surface by
influence of oscillation abrasive. First patent for
ultrasonic machining is from half 20th century.
Processing by ultrasound
Machining of strong and brittle material:
 ceramics,
 jewel and semi jewel,
 graphite,
 glass,
 Semi finished materials,
 Hardened and thermal resistant materials,
Principle of ultrasonic machining
Mechanical grinding influence of suspenzion
(substance of liquid and solid material) consisted
of abrasive mixtured in the liquid (water, oil,
petroleum, alcohol, ...).
Suspenzion is directed between tool and workpiece.
Tool is vibrated to frequency 20 kHz to 30 kHz.
Vibration of tool facing place are directed to
abrasive grains that impacted to machining
surface and removed the material.
Material removing
Material removing is possible by:
 Mechanical influence – elements of the abrasive
removed material in the straight impact –
abrasive influence,
 microginding - after impact of freely moving
abrasive particulate,
 Cavitations effect of abrasive suspension,
 Property and chemical action of liquid media in
suspension.
Kinematics of ultrasound
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Main movement – longitudinal tool vibrations
shift:
 longitudinal,
 Lateral,
 circular.
By movement combination and tool profile shape
(longitudinal and lateral) maybe realize different
operations of machining.
Specific field of application this
methods:
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Material cutting,
Groove and holes (circular or unsymmetrical shapes too)
deepening,
Deep holes boring – for barrel systems,
Milling and threading,
Polishing, ceramics grinding and lapping,
Machining of complex electrode on spark erosion,
Forming tool manufacturing from sintering carbide,
Rubber and thermoplastic cutting – clean cut without bur,
Composite material cutting and boring,
Diamond and gemstone shaping by using diamond dust or cubic
nitride boron into abrasive suspension
Ultrasound using in machining
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Ultrasound machining – ultrasound processing
the operation of machining, amplitudes abrasive
that removed material,
Machining aided by ultrasound – conventional
kinds of machining (f.e. turning) – tool that
realised machining is vibrated by ultrasound and
with respect of this are decreased cutting forces,
increased roughness and accuracy of the
machined surface...
Turning aided by ultrasound
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Turning of the strong and brittle materials,
cutting forces reduction, turning qualities and
accuracy improvements is observed at tool
vibration direction excitation parallel via the main
cutting motion (tangential vibration),
small amplitude (3 till 4 µm) increase tool
durability 3 till 7-times
Vibrations with big amplitude decrease the tool
durability,
Turning aided by ultrasound
Drilling aided by ultrasound
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Drilling of bore copper, aluminium alloy and
anticorrosive steel workpieces by lanced drill,
Chip crumbling is easier,
Higher productivity,
amplitude in interval 6 till 8 µm,
overall torque is reduced about 50 till 65%,
drill tools durability increase 2 till 3-times,
Higher dimension accuracy
Ultrasound drilling
Tool vibrated the abrasive in the
suspension,
 Material is removed by the same
mechanism as in the grinding,
 Used for the strong and brittle materials,
 High accuracy and production,
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Ultrasound drilling
Ultrasound drilling
Thread cutting aided by
ultrasound
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Lower friction, seizing is removed and decreased
is cutting force and overall torque,
Ultrasound vibrations influenced in tool axis
direction, amplitude is several µm,
For thread cutting is not need the set of taps,
Is possible to use the slot less screw-tap,
High quality of thread surface.
Smoothing by diamond and surface
strengthening
aided by ultrasound
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Plastic deformation of surface layer,
Small forces (approximately 200 – 300 N),
Ultrasound vibrations intensificated process of
smoothing and strengthening,
Increased micro strenghtness of surface
approximately 1,5 times,
Suitable positioning of the pressure intensity in the
surface layer,
Lower roughness of the surface,
High abradibility of the strengthnesses surface,
Higher lifetime of die tubes,
Smoothing by diamond and surface
strengthening
aided by ultrasound
Ultrasound grinding
Higher quality of the machined surface
 Higher tool lifetime,
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– focusing of tool,
 Tool cleaning,
 Self
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Using in the grinding circular and in the flat,
Machines for machining by
ultrasound
Machines for machining by
ultrasound
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magnetic transducer,
concentrator,
tool,
Ram,
against-weight,
Leading surfaces,
workpiece,
Pumping device,
tank,
weight.
Machines for machining by
ultrasound